Northeastern University researchers Gabriela Garcia and Laura Kuhl have investigated this daunting challenge of alternate bearing. This predatory cycle has plagued farmers for centuries. This phenomenon leads to crops exaggerating their production cycles, producing extreme swings in productivity. Within that context, their study pays particular attention to smallholdings, or family-run farms. Its goal is to introduce ways that farmers can change their practices to better mitigate natural variability.
Alternate bearing is an expensive phenomenon that greatly reduces agricultural productivity, especially in high-value crops such as coffee. In the high-yield years, plants tend to overcommit resources resulting in low-yield years following close behind. Garcia is an assistant professor of marine and environmental sciences and is co-appointed public policy and urban affairs. Creative Commons, Oleg Postoikov He stresses just how crucial it is to comprehend these variations.
Farmers are most vulnerable to making management blunders by misattributing any yield loss in alternate bearing years to mismanagement, Garcia states. What external, extrinsic sources of variability should be on your mind first, likely climate and changing rainfall or pest pressure.
Kuhl, an associate professor of public policy and urban affairs and international affairs, highlights the lack of research focused on the social dimensions of alternate bearing. “There are basically no studies that have looked at how farmers conceptualize it and its underlying drivers,” she explains. We hope that their work will continue to fill this gap by placing farmer perceptions and experiences front and center in the research.
Researchers found that some of the variability was inherent to the plants themselves. Farmers have developed innovative solutions to address challenges from outside the farm. Consider, for example, that most farmers use irrigation when facing drought conditions or pesticide application. The intrinsic variability due to alternate bearing is still not well understood.
Garcia’s previous work found that in years of high fruiting, the plants depleted their nitrogen reserves. This rapid drawdown undermines their ability to rejuvenate prior to the next harvest. “They overinvest resources during these high fruiting years,” she notes. “It takes them a year to recover those before they can reproduce again.”
Garcia and Kuhl are suggesting an integrated, holistic way of looking at yield variability. This method looks at what’s driving these factors at the plant level. This systems approach leads to a more holistic definition of resilience to farming systems. As Kuhl explains, understanding the eight types of variability is key to making smarter management decisions.
“These types of dynamics display really different patterns, and therefore different types of decisions need to be made about how to manage this type of variability,” she states.
Their results provide extremely useful information for developing sustainable agricultural practices. This is quite critical for coffee farmers facing the realities of alternate bearing.
“What it allows us to do is understand these feedbacks. So how did the ecological dynamics influence what kind of management practices,” – Gabriela Garcia